Private inspect tool
Image DPI Checker
Check whether an image has enough pixels to print cleanly. Processing stays in your browser.
Check the result yourself
Reproduce a 300 PPI / 150 PPI result
The original 1800 × 1200 PNG measures 300 PPI at 6 × 4 inches and 150 PPI at 12 × 8 inches. Try 6 × 6 inches to reveal an aspect-ratio mismatch.
Read the steps, expected results and limitations →More file tasks
Check an image's DPI and effective PPI online without Photoshop, then verify whether its pixel dimensions are suitable for the intended print size.
How it works
A useful result,
without the upload.
Check an image's pixel dimensions and effective print resolution online at any physical size without uploading the file. The file is decoded and processed inside this browser tab, so File Preflight never receives its contents.
Worked example
A 3600 × 2400 px image placed at 12 × 8 in has an effective resolution of 300 PPI.
How to use the Image DPI Checker
- Choose an image file or click the sample button to load a test image.
- Enter the intended print width in inches in the width field.
- Enter the intended print height in inches in the height field.
- Select your resolution target from the dropdown (150, 240, 300, or 600 PPI).
- Review the inspection summary showing effective PPI and whether it meets your target.
- Download a text report with the detailed resolution analysis if needed.
What happens under the hood
Your image is decoded locally using the browser's Image API, and its decoded pixel dimensions are divided by your intended print dimensions to calculate effective resolution. The calculation runs entirely in your browser without uploading the file. Results are displayed immediately, showing per-axis PPI and aspect ratio warnings when ratios differ.
Before you send the file
- The image is decoded locally and never sent to File Preflight.
- A metadata DPI value does not create detail; pixel dimensions determine available information.
- Inspect compression artifacts and focus quality in addition to the calculated resolution.
Frequently asked questions
What's the difference between metadata DPI and effective PPI?
Metadata DPI is just a tag and doesn't create detail. Effective PPI is calculated from actual pixel dimensions divided by intended print size. Only pixel count determines available information for printing.
Why does the tool show different PPI for width and height?
When image and print aspect ratios differ, the tool calculates PPI separately for each dimension. This shows you'll need to either crop the image or add borders to fit the intended size without distortion.
Can I check resolution for non-standard print sizes?
Yes, enter any positive decimal values for width and height. The tool calculates effective resolution for any custom print size you specify.
What does the aspect mismatch warning mean?
It means your image's aspect ratio doesn't match the print dimensions. Filling the size requires cropping; fitting the whole image adds borders. The calculation doesn't crop or stretch your file.
Keep an untouched original and inspect the downloaded file before replacing any production asset. Closing this tab removes the selected files from the tool.